This invention relates to an extruder and more particularly to an adapter for a die head of an extruder which splits the melt from the extruder into separate flow paths for movement to separate die heads.
Materials which are plasticized by an extruder such as polyvinyl chloride wherein the solid granular materials are heated and plasticized to issue as cylindrical shaped extrudate is very sensitive to overheating and subject to degradation. The improvements have been principally directed to extruder screw design and die head design to improve the homogeneous viscosity of the melt to assure a smooth flow of the plasticized material. It is also desirable to maintain this smooth flow of material in the die head adapter which splits the main flow from the extruder to into at least a pair of extrudates for extrusion from their respective die heads. The physical properties such as viscosity and velocity of flow are adversely affected by pronounced changes in the direction of flow as by movement past crevices or dead corners which tend to stagnate the flow of materials at such areas causing them to harden and tends to cause degradation in the material and adversely affects the end product. Through applicant's invention, there is a significant improvement in the unobstructed flow for the extrudate from the extruder through the adapter to the plural die heads. This is accomplished by having the respective conduits of the mating adapters and its associated parts with the die heads being circles presenting a perfect sealing between joints and surfaces. With the use of such adapters, the overall weight is reduced in the ratio of 3 to 1 in the case of small adapters and in ratio of 5 to 1 in the case of larger adapters thereby making it easier to handle and change as well as to facilitate the efficient dissipation of heat.